Being sensitive to the feelings of other people is a feature of an adult personality. Children develop this sense only gradually, and it is only during adolescence that it becomes readily recognizable, and an expectation of social behaviour. (Some people seem to be better at this skill than others.)

Psychologists refer to the ability to understand what other people feel, think and expect is called 'theory of mind'. It is another of the amazing and essentially human aspects of brain function. As with so many other of these features (such as our ability to imagine ourselves in different places, and at different times) it is a characteristic of the right front part of the brain.

What happens in the front parts of the brain (in particular the very front part, known as the prefrontal cortexCortexThe outer surface of the brain. and its many subdivisions) is an area of growing interest in dementia. For many years, we operated as though we believed that the brain was simply a passive recipient of the damage dished out to it by Alzheimer's diseaseAlzheimer's diseaseA neurological disease that affects memory and behaviour. It is characterized by beta-amyloid plaques and neurofibrillary tangles in the brain. There is no known cause but genetics and lifestyle are thought to play a role.. Over time, however, it is clear that the brain fights back. There are likely many forms in which the brain fights back, and these are covered by the general term 'neurocompensation'. For reasons that are not clear, neurocompensation appears to be particularly vigorous in the prefrontal cortex. Exactly how neurocompensation works is not clear. Indeed, it might even be that some parts of the neurocompensatory response make the effect of the disease worse. One way to think about how neurocompensation might make things worse is to consider what happens in arthritisArthritisA disease of the joints characterized by inflammation, pain, stiffness, and redness, a disorder of inflammation of the joints. Some types of arthritis appear to be initiated by infection with a bacterium. Over time, however, there is more damage caused by the persistent of chronicChronicA long-standing and continual disease process is referred to as being chronic. inflammation than there is by the bacterium itself. The same mechanisms that were helpful in an acuteAcuteWhen something is "acute", it means that it is generally short in duration and usually severe. response become harmful as a chronic response. Thus it might be that the progression of Alzheimer's disease arises from a faulty repair process that persists beyond what is helpful. Still, the idea of neurocompensation is opening new research avenues, by suggesting ways in which a helpful compensatory response might be enhanced, and a harmful one limited.